1. Field of the Invention
The present invention relates to the technical field of pressure sensors and more particularly to a pressure sensor of the surface acoustic wave type.
2. Description of the Related Art
To measure the pressure of a fluid, the use of pressure sensors comprising transducer elements with surface acoustic waves (SAW) or electro-acoustic transducers is generally known in the art. A particular sensor of this type is, for example, described in the U.S. Pat. No. 4,216,401 which relates in particular to a pressure sensor comprising a support structure in quartz which includes a bored cavity. The sensor comprises a flexible membrane which is coupled to the support structure in order to close the bored cavity on one side. One free surface of the flexible membrane includes one or more SAW electro-acoustic transducers with interdigital configuration electrodes. In one embodiment of the above-mentioned patent U.S. Pat. No. 4,216,401, the flexible membrane is made of piezoelectric material. In a second embodiment, the flexible membrane is made of non-piezoelectric material but a layer of piezoelectric material is deposited on the surface of the membrane.